LONDON , England -LRB- CNN -RRB- -- It is still remembered as one of the worst days in the history of modern sailing .

The Fastnet race still remains one of the biggest events in the yachting calendar .

Yet the Fastnet tragedy of 1979 in which 15 people were killed and ex-British leader Edward Heath went missing helped to usher in a new era of improved safety in the sport .

It was 30 years ago today that a freak storm struck over 300 vessels competing in the 600-mile yacht race between England and Ireland .

Mountainous seas and vicious high winds sunk or put out of action 25 boats .

The British rescue attempt turned into an international effort with a Dutch warship and trawlers from France also joining the search .

In spite of the biggest rescue operation launched by the UK authorities since the Second World War a total of 15 people died . Some of them drowned and others succumbed to hypothermia . Six of those lost went missing after their safety harnesses broke .

`` It was a catastrophic event that had far-reaching consequences for the sport , the biggest of which was in the design and safety of the boats , '' Rodger Witt , editor of the UK-based magazine Sailing Today told CNN .

`` Most people in the sailing community at the time knew someone who was involved in one way or another . I had a friend who lost his father . It was devastating . ''

In total 69 yachts did not finish the race . The former British prime minister , Edward Heath disappeared at the height of the storm , though he later returned to shore safe from harm . The corrected-time winner of the race was the yacht `` Tenacious '' , owned and skippered by Ted Turner , the founder of CNN .

Witt said that in the aftermath of the disaster the rules governing racing were tightened to ensure boats carried more ballast . Improvements were also made to the safety harnesses that tied crewmen to their boats , many of which proved ineffective in the tragedy . It also became mandatory for all yachts to be fitted with radio communication equipment and all competitors were expected to hold sailing qualifications to take part .

At the time of the tragedy the Fastnet race was the last in a series of five races which made up the Admiral 's Cup competition , the world championship of yacht racing .

Competitors from around the globe attempted the route which sets off from the Isle of Wight , off the English south coast , and rounds the Fastnet rock on the southeast coast of Ireland .

Roger Ware was in charge of handling press for the event on behalf of the organizers , the Royal Ocean Racing Club . Ware said that even today the tragedy `` still spooks me . '' The racers set off on a Saturday but it was n't till three days later that the authorities in the English coastal town of Plymouth realized there was a problem .

The press team was based at the Duke of Cornwall hotel in Plymouth and early Tuesday morning Ware got a call from his superiors to go to the hotel immediately in order to field calls from journalists .

`` The night before we 'd noticed high winds but there 'd been no forecast of bad weather so we did n't think much of it , '' Ware told CNN . `` As the morning progressed though , we heard that more and more boats were missing . It became obvious a tragedy was unfolding . ''

Ware said the worst part for him was fielding calls from concerned relatives . `` The Royal Ocean Racing Club headquarters was overloaded so calls were getting transferred to the press team .

`` I found myself talking to a woman whose husband I knew was in one of the boats where there 'd been fatalities . I could n't give her the information she wanted and to this day I still think about that telephone call . ''

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The 1979 Fastnet race ended in tragedy after a freak storm hit competitors

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In all 15 people died and the ex-British leader Edward Heath went missing for a time

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The disaster resulted in a raft of new safety rules introduced into the sport